With this hot weather we are having in the Pacific Northwest (and my XJS in my shop addressing an oil leak that made a new if my engine bay I detailed last winter), I have a renewed interest in getting my seldom used XJ12 back on the road.
A few issues to sort out:
There is a shudder. I just took it to the tire shop and they balanced the wheels (free of charge, nice of them). I took it for a drive after getting it back. It started out fine. Drove a couple miles on the interstate, exited, drove a couple miles on surface streets, got back on the interstate, and when I hit the brakes the shudder started again. And it’s not just when the brakes are applied, but that’s what starts it. I exited the freeway and continued getting a shudder whether or not the brakes were applied.
“Trac Fail” and “Anti Lock” lights are on.
Upon parking the engine temp crept up and there was a noticable amount of coolant on the ground. It was coming for the bottom side of the header tank (atmospheric catchment tank).
My thinking is
Front brake job for number 1.
Cleaning the wheel sensors for number 2.
And for what I’ve read on here, starting with a new call on the header tank for number 3.
If anyone has any further ideas, please let me know.
I would check the front calipers. I spent alot of money trying to solve the same problem on my Rolls Royce Silver Shadow. When driving the car (like yours), it would be silky smooth UNTIL I pressed the brake pedal a few times. After that, it drove terribly. Simple to check! Stop the car and touch the hubcap (rim) and see if one is very hot. With mine, the caliper was not releasing because of the brake hose not letting the brake fluid return to the reservior.
Thank you, Richard. That was along my line of thought. I was thinking maybe the rotors weren’t true and then the pads were being held a little too close (or progressively getting closer and closer with each press).